WONT STAY IDLEING

93 tracer, wont stay at idle, has senor replaces idle, air valve, could this be a problem with the fuel rail? Can that be the problem? Otherwise runs great except that problem, doesn't not idle ruff, oh, I noticed in summer with air on doesn't do that only like once, Gets great mileage 35 mpg on highway for the old girl am stuck any help? P.S. LOVE this site and do you guys work on cycles too? Love to see if u do. Thank u very much, your information make sit easy to do my own repairs.